Age and Month of Calving Adjustments of Holstein Protein, Milk, and Fat Lactation Yields
نویسندگان
چکیده
منابع مشابه
Evaluation of Various Approaches in Prediction of Daily and Lactation Yields of Milk and Fat Using Statistical Models in Iranian Primiparous Holstein Dairy Cows
In this research, 272977 test day records collected from 659 herds during years 2001 to 2011 by the Iranian animal breeding center were used. In the first section the ability of different models to predict daily milk yield from alternative milk recording was tested. The result showed that a complex model including noon milking time plus the effect of lactation curve of Ali and Schaeffer functio...
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Data containing 14,188 lactation and reproductive records of Korean Holstein cows at first parity distributed across 3734 herd-year-season groups were analyzed to get genetic (co)variance estimates for milk yield, fat yield, calving ease, and days open. Milk and Fat yields were adjusted to 305 d. Heritabilities and genetic correlations were estimated in two different animal models on which were...
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The contribution of a dilution effect to the relationship between milk yield and milk SCC was investigated using data from 24 Holsteins during the first 75 d after first calving. Bucket and quarter milk SCC were collected at weekly intervals. Individual milk weights were obtained at milking, and samples were obtained for determination of SCC. The milk weights at the corresponding a.m. milking o...
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The objective of this study was to estimates the genetic and environmental components for the lactation curve parameters, milk yield, age at first calving (AFC), calving interval (CI) and somatic cell count (SCC) in Iranian Holstein cows. The dataset consisted of 210625 test day records from 25883 cows with milk yield in the first parity recorded from July 2002 to September 2007 in a total of 9...
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Percentages and yields of fat, crude protein (CP), true protein (TP) and non-protein nitrogen (NPN) wereassessed in milk of four groups of Holstein cows, at early, mid and late lactation (days in milk 20-70, 71-110, 111-150 and 151-210), on a diet rich in concentrates during a hot summer. Four milk samples were taken from individual cows at 10-day intervals. Milk fat percentages were close to b...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1982
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(82)82397-7